This application is based upon and claims the benefit of priority from Japanese Patent Application No. 2018-219709, filed on Nov. 22, 2018 and 2019-040873, filed on Mar. 6, 2019 the entire contents of both of which are incorporated herein by reference.
Embodiments described herein relate generally to a liquid discharge head, a flow path member, and an inkjet printer.
In the related art, a flow path member having a chamber in a direction orthogonal to a flow path of a liquid flowing in one direction has a problem that it is difficult for the liquid to circulate in the chamber. For example, as the flow path member, a liquid discharge head which discharges a liquid such as ink used in a printing apparatus or the like can be mentioned. The liquid discharge head has a function of discharging a liquid in a pressure chamber from a nozzle by deformation of the pressure chamber which discharges the liquid. However, when it is difficult for the liquid to circulate in the pressure chamber, the liquid in the nozzle is dried and thickened during printing standby.
Embodiments provide a liquid discharge head and a flow path member capable of circulating a liquid in a chamber with a simple configuration.
In general, according to one embodiment, a liquid discharge head includes a plate and a flow path base. The plate includes a pressure chamber which is opened to one main surface, a liquid introduction portion which converts a flow direction of a liquid to a flow toward the pressure chamber on a secondary side of the flow direction of the liquid at an opening of the pressure chamber, and a nozzle which is connected to the pressure chamber, is opened to the other main surface, and discharges the liquid. The flow path base is provided on one main surface side of the plate and forms a liquid chamber in which the liquid flows with the plate along a surface direction of the one main surface.
Hereinafter, a liquid discharge apparatus 1 having a liquid discharge head according to a first embodiment will be described with reference to
As shown in
The paper feeding cassette 11 accommodates a plurality of recording papers P. The paper feeding cassette 11 is disposed in the housing 10. The paper discharge tray 12 is disposed in the upper part of the housing 10. The paper discharge tray 12 receives the discharged recording paper P on which an image is formed.
The conveying device 14 has a plurality of guides and a plurality of conveyance rollers disposed along a path along which the recording paper P is conveyed. The conveyance roller is driven by a motor to rotate and thus conveys the recording paper P from the paper feeding cassette 11 to the paper discharge tray 12.
The holding roller 13 has a cylindrical frame formed of a conductor and a thin insulating layer formed on the surface of the frame. The frame is connected to ground. The holding roller 13 conveys the recording paper P by rotating while holding the recording paper P on the surface thereof.
The holding device 15 causes the recording paper P carried out from the paper feeding cassette 11 by the conveying device 14 to adhere to the outer peripheral surface of the holding roller 13 and causes the holding roller 13 to hold the recording paper. After pressing the recording paper P against the holding roller 13, the holding device 15 causes the recording paper P to adhere to the holding roller 13 by electrostatic force due to charging.
The image forming device 16 forms an image on the recording paper P held on the outer surface of the holding roller 13 by the holding device 15. The image forming device 16 includes a plurality of liquid discharge heads 21 facing the surface of the holding roller 13, a plurality of ink tanks 23 connected to the plurality of liquid discharge heads 21, and a plurality of control units 24 connected to the plurality of liquid discharge heads 21. The plurality of liquid discharge heads 21 form an image by discharging, for example, cyan, magenta, yellow, and black inks of four colors onto the recording paper P, respectively.
The liquid discharge head 21 is connected to the ink tank 23 containing ink of the corresponding color. The liquid discharge head 21 discharges ink droplets onto the recording paper P held by the holding roller 13 to form characters and an image.
As shown in
As shown in
As shown in
As shown in
As shown in
As shown in
As shown in
As shown in
As shown in
As shown in
As shown in
As shown in
Further, for example, the width of the liquid introduction portion 56 in the direction orthogonal to the flow direction of the liquid flowing in the common liquid chamber 51 is smaller than half of the width of the pressure chamber 54 in the direction orthogonal to the flow direction of the liquid flowing in the common liquid chamber 51. That is, the width of the liquid introduction portion 56 in the direction orthogonal to the flow direction of the liquid flowing in the common liquid chamber 51 is smaller than the radius of the pressure chamber 54. The liquid introduction portion 56 is disposed to be shifted in a direction orthogonal to the flow direction of the liquid flowing in the common liquid chamber 51 from the center of the pressure chamber 54 in the flow direction of the liquid flowing in the common liquid chamber 51 and the end in the direction orthogonal to the flow direction of the liquid flowing in the common liquid chamber 51.
As shown in
As shown in
As shown in
As shown in
According to the liquid discharge head 21 of the liquid discharge apparatus 1 configured as described above, when some of the liquid flowing in the common liquid chamber 51 hits the end face of the liquid introduction portion 56, the flow of some of the liquid is converted into a flow toward the pressure chamber 54 by the end face of the liquid introduction portion 56. Therefore, the liquid discharge head 21 can guide some of the liquid flowing in the common liquid chamber 51 to the pressure chamber 54 by the liquid introduction portion 56. Since the liquid can be introduced into the pressure chamber 54, the generation of the flow of the liquid in the pressure chamber 54 prevents the liquid from staying in the pressure chamber 54 and increasing the viscosity of the liquid.
In addition, by making the width of the liquid introduction portion 56 in the direction orthogonal to the flow direction of the liquid flowing in the common liquid chamber 51 smaller than the width of the pressure chamber 54, the flow returning to the common liquid chamber 51 from the pressure chamber 54 can be generated. As a result, since the flow in which the liquid is introduced into the pressure chamber 54 and the flow in which the liquid is discharged from the pressure chamber 54 are generated, the liquid discharge head 21 can guide the liquid to the pressure chamber 54 more easily.
As described above, since the liquid in the pressure chamber 54 circulates even during printing standby, the liquid discharge apparatus 1 can prevent the liquid in the nozzles from being dried and thickened during printing standby.
The liquid introduction portion 56 is a protrusion having an inclined surface which is provided on the secondary side of the pressure chamber 54 in the flow direction in which the liquid in the common liquid chamber 51 flows. Therefore, the liquid discharge head 21 can introduce the liquid into the pressure chamber 54 only by providing the liquid introduction portion 56 having a simple configuration.
As described above, according to the liquid discharge apparatus 1 according to the first embodiment, the liquid introduction portion 56 which converts the flow direction of the some of the liquid flowing in the common liquid chamber into a flow toward the pressure chamber 54 is provided on the secondary side of the pressure chamber 54 of the liquid discharge head 21. Therefore, the liquid discharge head 21 can introduce the liquid into the pressure chamber 54 with a simple configuration.
Next, a liquid discharge head 21A used in a liquid discharge apparatus 1 according to a second embodiment will be described using
As shown in
The liquid discharge head 21A includes, for example, the common liquid chamber 51, the suction port 52, the discharge port 53, the plurality of pressure chambers 54, the plurality of nozzles 55, a plurality of liquid introduction portions 56A, the drive elements 57, and the electrodes 58. Further, as shown in
As shown in
As shown in
Further, the width of the first liquid introduction portion 71 in the direction orthogonal to the flow direction of the liquid flowing in the common liquid chamber 51 is smaller than half of the width of the pressure chamber 54 in the direction orthogonal to the flow direction of the liquid flowing in the common liquid chamber 51. That is, the width of the first liquid introduction portion 71 in the direction orthogonal to the flow direction of the liquid flowing in the common liquid chamber 51 is smaller than the radius of the pressure chamber 54. The first liquid introduction portion 71 is disposed to be shifted in a direction orthogonal to the flow direction of the liquid flowing in the common liquid chamber 51 from the center of the pressure chamber 54 in the flow direction of the liquid flowing in the common liquid chamber 51 and the end in the direction orthogonal to the flow direction of the liquid flowing in the common liquid chamber 51.
As shown in
According to the liquid discharge head 21A configured as described above, some of the liquid flowing in the common liquid chamber 51 flows through the first liquid introduction portion 71 and hits the second liquid introduction portion 72, and then some of the liquid is converted into the flows toward the inside of the pressure chamber 54 and the outside of the pressure chamber 54 by the second liquid introduction portion 72. The liquid is introduced into the pressure chamber 54 by the flow toward the inside of the pressure chamber 54.
Thus, the liquid discharge head 21A can guide some of the liquid flowing in the common liquid chamber 51 to the pressure chamber 54 by the liquid introduction portion 56A. Since the liquid can be introduced into the pressure chamber 54, the flow of the liquid in the pressure chamber 54 is generated and thus it is possible to prevent the liquid from staying in the pressure chamber 54 and increasing the viscosity of the liquid.
In addition, by making the width of the liquid introduction portion 56A in the direction orthogonal to the flow direction of the liquid flowing in the common liquid chamber 51 smaller than the width of the pressure chamber 54, the flow returning to the common liquid chamber 51 from the pressure chamber 54 can be generated. Thus, the flow in which the liquid is introduced into the pressure chamber 54 and the flow in which the liquid is discharged from the pressure chamber 54 are generated so that the liquid discharge head 21A can more easily guide the liquid to the pressure chamber 54.
Further, the liquid can be introduced into the pressure chamber 54 by the liquid introduction portion 56A with a simple configuration in which the first liquid introduction portion 71 that is a groove along the flow direction of the liquid in the common liquid chamber 51 in the one main surface of the plate 61, and the second liquid introduction portion 72 is formed as a part of the wall portion of the pressure chamber 54.
As described above, according to the liquid discharge head 21A in the liquid discharge apparatus 1 according to the second embodiment, the liquid introduction portion 56A which converts the flow direction of some of the liquid flowing in the common liquid chamber 51 into the flow toward the pressure chamber 54 is provided on the secondary side of the pressure chamber 54. Therefore, since the liquid discharge head 21A can introduce the liquid into the pressure chamber 54 with a simple configuration, the liquid in the pressure chamber 54 can be circulated.
In addition, this embodiment is not limited to the above-described example. For example, in the above-described example, an example in which the pressure chamber 54 is a cylindrical space in the liquid discharge heads 21 and 21A is described, but there is no limitation thereto. For example, the pressure chamber 54 may have a rectangular columnar shape or an elliptical columnar shape, or may have a shape in which a plurality of cylindrical spaces are continuous or a truncated cone shape. In the example described above, the drive element 57 is provided on the other main surface of the plate 61 and around the nozzles 55, but there is no limitation thereto. For example, the drive element 57 may be integrally provided on the wall portion of the pressure chamber 54.
Further, in the above-described example, an example in which the liquid discharge heads 21 and 21A are used as the flow path members, the first chamber is used as the common liquid chamber 51, the second chamber is used as the pressure chamber 54, and the plate 61 and the flow path base 62 are used as the flow path portion is used and described, but there is no limitation thereto. That is, as long as a structure in which there is a closed or substantially closed chamber in a direction orthogonal to the flow direction of the liquid on the flow path through which the liquid flows in one direction is provided, the liquid introduction portion 56 can be applied. For example, as in a flow path member 21B in a third embodiment shown in
The flow path member 21B having such a configuration is, for example, provided with the liquid introduction portion 56B having an inclined surface inclined toward the port 81a on the secondary side of a branch portion 81b branched to the port (chamber) 81a where the sprinkler head 82 of the flow path portion 81 is provided. With such a configuration, in the flow path member 21B, due to some of water, which is a liquid flowing in one direction in the flow path portion 81, flowing toward the port 81a in the liquid introduction portion 56B, even when the port 81a is closed by providing the sprinkler head 82, water is introduced to the port 81a. Thus, water does not stay in the port 81a. Therefore, the effect of preventing the concentration of chlorine contained in the water in the port 81a from being reduced and preventing precipitates from being deposited and the effect of preventing of malfunction of the sprinkler head 82, preventing use of unsanitary water as drinking water, and preventing the discharge of unsanitary water from the sprinkler head 82 can be exhibited. As described above, in the case of the flow path member in which the chamber exists in the direction orthogonal to the flow direction of the liquid on the flow path through which the liquid flows in one direction, the liquid introduction portion can be used appropriately.
Further, in the above-described example, the configurations of the liquid discharge heads 21 and 21A are described, but, for example, a method of manufacturing the liquid discharge heads 21 and 21A can be set appropriately. Next, a method of manufacturing a liquid discharge head 21 used in the liquid discharge apparatus 1 according to a fourth embodiment will be described with reference to
Since the configuration of the liquid discharge head 21 according to the fourth embodiment is the same as the configuration of the liquid discharge head 21 according to the first embodiment described above except for the manufacturing method and the material of the liquid introduction portion 56, the same components as those of the liquid discharge head 21 according to the first embodiment described above are denoted by the same reference numerals, and the detailed description thereof will be omitted.
As the example of the method of manufacturing the liquid discharge head 21, an example in which the plurality of liquid introduction portions 56 are formed on the plate 61 will be described below with reference to
The liquid introduction portion 56 according to the embodiment is formed of, for example, a photosensitive resin material. The liquid introduction portion 56 is formed by photolithography.
As shown in
Next, a mask 110 is provided on the photosensitive resin material 100 applied to the plate 61 (ACT 3). The mask 110 is formed in the shape of the main surface of the liquid introduction portion 56 and is provided at least in a region where the liquid introduction portion 56 of the photosensitive resin material 100 is to be formed.
Next, the photosensitive resin material 100 applied onto the plate 61 is exposed from the mask 110 side (ACT 4). As a specific example, light is emitted from a light source provided at a position separated from the plate 61 in the direction orthogonal to the main surface direction of the plate 61, and the pattern of the mask 110 is transferred. Here, for example, the light is ultraviolet light.
Next, the mask 110 is removed, and the photosensitive resin material 100 is developed (ACT 5). As a specific example, for example, the plate 61 containing the photosensitive resin material is immersed in a developer, or a developer is sprayed. Thus, the exposed photosensitive resin material 100 is dissolved in the developer, and the exposed photosensitive resin material 100 is removed from the plate 61. Thus, the photosensitive resin material 100 in the region where the mask 110 is formed and the liquid introduction portion 56 is to be formed remains on the plate 61. That is, the photosensitive resin material 100 remaining on the plate 61 after development constitutes the liquid introduction portion 56. In addition, when some of the light emitted from the light source at the time of exposure passes through a region not covered by the mask 110, the incident direction is inclined relative to the main surface of the plate 61 or the normal to the main surface of the photosensitive resin material 100. For this reason, as shown in
The liquid introduction portion 56 of the liquid discharge head 21 configured as described above is molded by photolithography. In addition, since the end face on the pressure chamber 54 side of the liquid introduction portion 56 is inclined in the liquid introduction portion 56 by providing the mask 110 on the photosensitive resin material 100 and performing an exposure process, the liquid introduction portion 56 can be easily formed.
Moreover, according to the liquid discharge head 21 manufactured as described above, similar to the liquid discharge head 21 according to the first embodiment described above, the liquid in the chambers 54, 81a can be circulated with a simple configuration.
Next, a method of manufacturing the liquid discharge head 21A used in the liquid discharge apparatus 1 according to a fifth embodiment will be described with reference to
Since the configuration of the liquid discharge head 21A according to the fifth embodiment is the same as the configuration of the liquid discharge head 21A according to the second embodiment described above except for a configuration further including a third plate 120 as a member constituting the liquid introduction portion 56A, the same components as those of the liquid discharge head 21A according to the second embodiment described above are denoted by the same reference numerals, and the detailed description thereof will be omitted.
The plate 61 of the liquid discharge head 21A further includes the third plate 120 on the surface of the first plate 61a of the plate 61. That is, the plate 61 is formed by integrally bonding the first plate 61a, the second plate 61b, and the third plate 120.
The third plate 120 is a member fixed to the surface of the first plate 61a by an adhesive or the like. The third plate 120 has, for example, a plurality of openings 120a that constitute the first liquid introduction portion 71 and the second liquid introduction portion 72 including a part of the pressure chamber 54.
Next, an example of the method of manufacturing the liquid discharge head 21A will be described. First, the third plate 120 is molded. As a specific example, the plate-like member 120 is processed by punching, etching, electroforming, and the like. The plurality of openings 120a for forming the liquid introduction portion 56A in the plate 61 are formed in the third plate 120. Next, the third plate 120 in which the plurality of openings 120a are formed is attached and fixed to the surface of the first plate 61a by an adhesive or the like. The second plate 61b is also fixed to the first plate 61a. By integrally assembling the first plate 61a, the second plate 61b, and the third plate 120 through these processes, the plate 61 having the liquid introduction portion 56A in the pressure chamber 54 is formed. Next, by integrally assembling the plate 61 and the flow path base 62, the liquid discharge head 21A is manufactured.
In the liquid discharge head 21A configured as described above, for example, the liquid introduction portion 56A is formed by the plurality of plates 61a, 61b, and 120 for the plate 61. Then, the first liquid introduction portion 71 and the second liquid introduction portion 72 are provided in advance on the third plate 120 constituting the common liquid chamber 51 side of the plate 61, and the plate 120 is assembled integrally with the other plates 61a and 61b to constitute the plate 61.
Thus, the first liquid introduction portion 71 is formed by the surface of the first plate 61a and the openings 120a of the third plate 120. In addition, the second liquid introduction portion 72 is formed by the openings 120a of the third plate 120. Further, the plate 61 including the liquid introduction portion 56A is manufactured with a simple structure in which the openings 120a constituting the first liquid introduction portion 71 and the second liquid introduction portion 72 are processed to the third plate 120, and the plurality of plates 61a, 61b, and 120 are integrally assembled. Further, the process of forming the liquid introduction portion 56A into the third plate 120 may be a relatively easy processing method such as punching, etching, and electroforming, and the manufacture of the liquid discharge head 21A becomes easy.
Moreover, according to the liquid discharge head 21A manufactured in this manner, the liquid in the chambers 54 and 81a can be circulated with a simple configuration, as in the liquid discharge head 21A according to the second embodiment described above.
As in the liquid introduction portion 56A according to the second embodiment described above, when the depth of the primary side of the first liquid introduction portion 71 becomes gradually deeper from the primary side to the secondary side, and the intermediate portion of the primary side is configured to have a predetermined depth to the secondary side, the liquid introduction portion can be easily formed by forming the openings 120a of the third plate 120 by etching and adjusting the amount of etching.
According to the liquid discharge heads 21 and 21A or the flow path member 21B according to at least one embodiment described above, it is possible to circulate the liquid in the chambers 54 and 81a with a simple configuration.
While certain embodiments have been described, these embodiments have been presented by way of example only, and are not intended to limit the scope of the inventions. Indeed, the novel embodiments described herein may be embodied in a variety of other forms; furthermore, various omissions, substitutions and changes in the form of the embodiments described herein may be made without departing from the spirit of the inventions. The accompanying claims and their equivalents are intended to cover such forms or modifications as would fall within the scope and spirit of the inventions.
Number | Date | Country | Kind |
---|---|---|---|
2018-219709 | Nov 2018 | JP | national |
2019-040873 | Mar 2019 | JP | national |